Ordinarily, after an offshore platform has fulfilled its use by extracting all the oil or gas it can from a given location, it is merely discarded. Typically, the platforms are removed to 15 feet below the mudline. Oil companies routinely pay millions of dollars to have the platforms removed and the platforms often become the property of the remover. Many of these platforms are lowered to the seabed in approved dumping sites and are in excellent condition. As a result, the platforms could be re-used for other purposes such as power generation.
U.S. Pat. No. 3,946,568 is directed to an offshore oil production platform comprising one section disposed on the sea bed and another section connected to the one section and projecting up above the sea surface. The one section consists of a plurality of prefabricated units comprising at least one tank divided into a plurality of compartments and having a peripheral wall the thickness of which is not adapted to withstand full water pressure with the tank empty in the submerged state, and at least one compartment in the tank has a peripherial wall the thickness of which is adapted to withstand full water pressure when empty in the submerged state.
U.S. Pat. No. 5,188,484 is directed to a mobile, self-elevating, offshore production platform, for exploitation of smaller reservoirs, with a liquid tight hull having a deck; a plurality of support legs, each having a gear rack and bottom footpads, which are slidably extendable through the hull; a removable jacking tower for each support leg, and, a locking means for each support leg which is engageable to the leg gear rack at any vertical position of the leg. Mineral processing equipment is pre-installed on the deck at a suitable shoreside facility. Then the platform, with legs elevated, is towed to the offshore location where minerals are to be produced. On location the legs are lowered, grounded, and then pre-loaded to desired criteria by introducing ballast water into the hull. After pre-loading the platform is deballasted and elevated to establish a desired air gap. Upon elevation a locking device is engaged to secure each leg in place and the jacking towers, tower powering equipment, and ballast pumps may then be completely removed for storage, or reuse on other platforms. Installation is completed by connecting the hydrocarbon processing equipment to influent and effluent means provided. Upon depletion of the mineral reservoir, or for other reasons such as the threat of a violent storm, the platform can be removed from one location, and reused at another, by reversing and repeating the above procedure.
U.S. Pat. No. 6,139,224 is directed to a semi-submersible platform for offshore oil operation comprising a buoyant sub-structure comprising a base and a plurality of columns upstanding from said base, a buoyant deck-hull mounted on the columns and means for ballasting and deballasting at least the base of said sub-structure. It further comprises means for tangentially guiding said deck-hull on said columns during deployment of the platform into a predetermined configuration by ballasting of the sub-structure while the deck-hull is floating and means for locking said deck-hull to the columns in said predetermined configuration.
U.S. Pat. No. 5,573,355 is directed to an offshore oil drilling or producing platform comprising a hull carried by legs provided with feet adapted to rest on the sea bed, characterized in that the walls of each of the legs define a space opening onto the respective foot in which are retracted anchoring piles for the leg carried by the foot, each leg being also provided in its upper part with support means in vertical alignment with the piles within the space defined by the walls of the leg for supporting a device for driving the piles into the sea bed.
U.S. Pat. No. 4,025,220 is directed to a fluid-current energy-conversion plant, especially useful for electricity generation, utilizing an axial flow turbine as the energy conversion element, has self-inflated flexible collector elements for capturing a portion of the fluid current, increasing its velocity, guiding at least some of each portion into the turbine's mouth, then returning the captured flow into the stream.
None of the above inventions provide a re-usable offshore oil platform to provide an alternative energy source. It would therefore be beneficial if an alternative energy source utilizing the re-use of decommissioned oil platforms existed to harness energy.